From German Pat. No. 202,024 a stove has become known wherein a stack of hollow ring members disposed above a combustion chamber define a central vertical duct surrounded by several annular compartments with inclined internal deflector and adjoining top and bottom apertures enabling flue gases rising through the central duct to descend progressively through the several annular compartments in each of which they describe a full circle. Air present in an annular channel bounded by a jacket surrounding the stack is heated by the circulating gases which escape through an outlet of the lowermost ring member.
The disadvantage of this known stove resides in the complicated construction of its ring members which can be manufactured only with relatively high expenditure. Moreover, the complicated guidance of the flue gases can quickly lead to considerable deposits, especially in the region of the deflectors and apertures, whereby the combustion in the stove is significantly impaired.